What are the differences between unsigned integers and signed integers?

The difference between unsigned integer and signed integer: 1. Numeric range; 2. Symbol processing method. Detailed introduction: 1. Numerical range. The value range of unsigned integer type is non-negative, while the value range of signed integer type includes positive numbers, negative numbers and zero. This is because in unsigned integer type, all bits are Used to represent numerical values, and in signed integers, the highest bit is used to represent symbols; 2. Sign processing method, signed integers use two's complement to represent numerical values, including a sign bit, which is used to represent numerical values. The positive and negative bits are used to represent the value itself, etc.

Unsigned integer and signed integer are two commonly used data types in computer programming. The main difference between them is that they represent numeric range and symbol processing.

1. Value range: The value range of unsigned integer types is non-negative, while the value range of signed integer types includes positive numbers, negative numbers and zero. This is because in unsigned integers, all bits are used to represent the numeric value, whereas in signed integers, the highest bit is used to represent the sign. For example, a 16-bit unsigned integer variable can represent a value in the range 0 to 65535 (2^16 - 1 = 65536 - 1), while a signed integer can represent a value in the range -32768 to 32767.

2. Sign processing method: Signed integers use two's complement to represent values, including a sign bit. The sign bit is used to represent the sign of the value, and the remaining bits are used to represent the value itself. Unsigned integers have no sign bit, and all bits are used to represent numerical values.

In addition, the way unsigned integers and signed integers are stored in memory is also different. Signed integers use the highest bit (usually bit 31) as the sign bit, while negative numbers are represented in two's complement form. Unsigned integers have no sign bit, and all bits are used to represent numerical values.

In programming languages, different data types can be used to represent unsigned integers and signed integers. For example, in C language, you can use the "unsigned" keyword to declare unsigned integer variables, while integer variables declared by default are signed. Similarly, in Python, you can use the "int" type to represent signed integers, and unsigned integers can be represented by "unsigned int".

When choosing to use unsigned integer or signed integer, you need to consider based on specific needs. When dealing with values ​​that may take negative values, signed integers should be used; when dealing with non-negative values, such as indexes, loop counters, etc., unsigned integers may be more appropriate.

It should be noted that although unsigned integers and signed integers are similar when representing positive numbers and zero, they behave differently when dealing with negative numbers. Signed integers can represent negative numbers, while unsigned integers can only represent non-negative numbers. Therefore, when choosing to use unsigned integers or signed integers, you need to consider based on specific needs.

To sum up, the main difference between unsigned integers and signed integers lies in their numerical range and symbol processing. The value range of the unsigned integer type is non-negative and is suitable for dealing with non-negative integers, while the signed integer type has a wider range of values ​​and can represent positive numbers, negative numbers and zero, and is suitable for dealing with possible negative values. numerical value. Specific needs should be considered when choosing to use.

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